So many drinking water treatment plants are under various difficulties by new reinforced effluent standards. Since the target turbidity, much higher than annual average, for designing sludge thickener have to be set to confront high turbidity season, the sludge at thickener should be put up for a long time during usual days. So the soluble manganese and chloroform may be formed under the anaerobic environment in the sludge thickener when the sludge retention time is longer with low turbidity. This phenomenon results in difficulties to keep regulatory level of the discharged effluent. For an effort to overcome the problems, a sludge aeration was successfully implemented into the thickening process. As a result, the final effluent quality and sludge volume were much improved; 41 % of manganese, 62 % of chloroform and 35 % of sludge volume. Additionally, effluent quality was improved ; 61 % of Manganese on aeration with pH control and we could make sure of stability effluent quality despite a long sludge retention time. We recommended the standard of installation sludge aeration equipment to nationally supply water treatment plant under effluent water quality problem ; Manganese, Chloroform, etc.

정수장 슬러지는 수 처리 역 세척 과정에서 발생되는데, 기계적인 방법 또는 자연건조방법으로 탈수된 후 주로 해양투기, 매립등의 방법으로 처리한다. 최근에는 런던협약에 의해 해양투기가 상당히 제약을 받고 있다. 탈수된 정수장 슬러지를 위생매립장의 복토재로서의 활용가능성을 파악하기 위하여 실내실험을 통하여 정수장슬러지의 물리 화학적 특성과 지반공학적 특성을 파악하였다. 슬러지의 지반공학적 특성을 향상시키기 위하여 슬러지에 일반토사를 혼합한 시료에 비중계실험, 액 소성한계실험 비중실험, 다짐실험. 일축압측 실험등을 실시하였다. 슬러지에 일반토사를 혼합한 혼합토는 정수장슬러지와 비교하여 최대건조단위증량은 증가하고, 최적함수비는 감소하였고, 최대압축응력과 마찰각을 증가한 반면 점착력은 감소하였다. 미국환경청의 복토재 기준을 확보하기 위해서 슬러지와 일반토사를 3:7로 혼합하여야 하며, 혼합토의 압축강도는 3.6kg/cm2이다.

This study was conducted to recover the aluminum from water treatment plant sludge containing alumina. The optimum reaction conditions about chlorination of sludge with NH4Cl are as follows: the weight ratio of sludge to NH4Cl is 4, the reaction time is 60min, and the temperature is 300℃. And the result of leaching time test showed that the highest yield of alumina at 160℃ was 96% but the result of leaching test at 160℃ was little better than that of leaching test at 100℃ while the leaching concentration of HCl was 4N. The optimum reaction conditions of chlorinated sludge with NH4Cl, gave the highest yield of 95.41% based on aluminum.